I decided to shape the ribcage a bit more naturally.
The neck is based partly on horse anatomy but very stylized.
piz: Thank you!
smeagol: These are just ZBrush renders. I turn 'Document>Range' to '0' which coincidentally turns the background the same color as the forum background. My renders are slightly darker because I 'shadowbox' them by turning up 'Render>Preview Shadows>Backshadow'.
fishadder: Thank you!
reminator: Hehe, I do get carried away...